React Native Accelerometer maximum frequency test

accelerometertest.js

//Maximum i could get on Iphone was 100 Hz, if someone has idea to improve on this, let me know in comments
//Android i could get around 160 hz
//Both test were done on https://snack.expo.dev/ by pasting the below code and testing on expo app.
//For android i have read the following
//If you need an update interval less than 200ms, you should: add android.permission.HIGH_SAMPLING_RATE_SENSORS to app.json permissions field
//or if you are using bare workflow, add <uses-permission android:name="android.permission.HIGH_SAMPLING_RATE_SENSORS"/> to AndroidManifest.xml.

import React, { useState, useEffect } from 'react';
import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
import { Accelerometer } from 'expo-sensors';
var count = 0;
var dispCount = 0;
var currTime = 0;
var lastTime = 0;
export default function App() {
  const [{ x, y, z }, setData] = useState({
    x: 0,
    y: 0,
    z: 0,
  });
  const [subscription, setSubscription] = useState(null);

  const _slow = () => Accelerometer.setUpdateInterval(1000);
  const _fast = () => Accelerometer.setUpdateInterval(2);
  const _subscribe = () => {
    count = 0;
    lastTime = Date.now();
    setSubscription(
      Accelerometer.addListener(accelerometerData => {
        const { x, y, z } = accelerometerData;
        setData(accelerometerData);
        currTime = Date.now();
        count = count + 1;
        if ((currTime - lastTime) > 1000) {
          lastTime = currTime;
          dispCount = count;
          count = 0;
        }
      })
    );
  };

  const _unsubscribe = () => {
    subscription && subscription.remove();
    setSubscription(null);
  };

  useEffect(() => {
    _subscribe();
    return () => _unsubscribe();
  }, []);

  return (
    <View style={styles.container}>
      <Text style={styles.text}>Accelerometer: (in gs where 1g = 9.81 m/s^2)</Text>
      <Text style={styles.text}>x: {x}</Text>
      <Text style={styles.text}>y: {y}</Text>
      <Text style={styles.text}>z: {z}</Text>
      <Text style={styles.text}>hz: {dispCount}</Text>
      <Text style={styles.text}>cTime: {currTime}</Text>
      <Text style={styles.text}>lTime: {lastTime}</Text>

      <View style={styles.buttonContainer}>
        <TouchableOpacity onPress={subscription ? _unsubscribe : _subscribe} style={styles.button}>
          <Text>{subscription ? 'On' : 'Off'}</Text>
        </TouchableOpacity>
        <TouchableOpacity onPress={_slow} style={[styles.button, styles.middleButton]}>
          <Text>Slow</Text>
        </TouchableOpacity>
        <TouchableOpacity onPress={_fast} style={styles.button}>
          <Text>Fast</Text>
        </TouchableOpacity>
      </View>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    paddingHorizontal: 20,
  },
  text: {
    textAlign: 'center',
  },
  buttonContainer: {
    flexDirection: 'row',
    alignItems: 'stretch',
    marginTop: 15,
  },
  button: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#eee',
    padding: 10,
  },
  middleButton: {
    borderLeftWidth: 1,
    borderRightWidth: 1,
    borderColor: '#ccc',
  },
});